Separable attachment-plug.



H. HUBBELL. SEPARABLE ATTACHMENT PLUG. urmommn FILED APB.23,1910.

Patented June 6,1911.

4 INVENTUR ATTORNEY through the shell and isjprovided at its for- UNITED STATESWPATENT OFFICE.

HARVEY I-IUBBEL'L, OF BRIDGEPORT, CONNECTICUT.

SEPARABLE ATTACHMENT-PLUG.

Specification of Letters Patent.

Patented June 6, 1911.

Application filed April 23, 1910. Serial No. 557,169.

In all whom it may concern:

Be it known that 1, IlAIWEY IlUnnnLn, a citizen of the United States, residing at 'Ilridgeport, county of Fairfield, State of Connecticut, have invented an Improvement in Scparablc Attachmentillugs, of which the following is a specification.

This invention relates tosc parable attachmcnt plugs and has t'or its object to simplify, cheapen and generally improve their construction and mode of operation.

With these ends in view I have devised the simple and novel attachment plug which I will. now describe, referring to the accompanying drawing forming a part of this specification and using reference characters toindicate the several parts.

Figure 1 is. a longitudinal section of my novel plug on an enlarged scale, the members being engaged; Fig. 2 a section on the line 2-2 in Fig. 1,1ooking in the direction of the arrow; Fig. 3 a plan View of the outer member showing the interior thereof, and Fig. 4 is an end View of the inner member.

7 10 denotes the screw shell which is adapted to engage a receptacle (not shown) and has rigidly secured at its forward end an in sulating button or head 11. At the opposite end of the screw shell is a knurled insulating ring,12 for convenience in operation and be low the knurled ring is an insulating sleeve 13, both of which are retained in place by closing the metal of the shell about tlll'l'l: At the inner end of the screw thread and contiguous to the insulating ring is :1 circumferential groove 14, the purpose of which will presently be explained. Upon the outer side of thcinsulati-ng head is a contact plate and on the inner side thereof is a contact spring 16, said contact'plate and contact spring being connected bya screw 17 by which both are rigidlysccured to the insulating head. The screw shell and the parts carried thereby have been referred to as the outer member. The inner member comprises an inner shell, indicated by 1.8, and an insulating block 19 which lies within the shell and is retained against forward movement by a flange 20 at the forward end of the shell. The insulating block projects ward end with a contact plate 21 which is adapted to engage contact spring 16 in the assembled position. The inner shell carries a plurality of cking springs22, in the present instance t ee, which are provided with projections 23 adapted to engage circular groove i l in the screw shell to lock the members in the assembled position. I have shown these springs as riveted to the inner side of the inner shell and the projections as extending through openings 24 in the shell, although these special details of constructionare immaterial so liar as the principle of the invention is concerned. At the rear end of the inner shell is a screw thread 25 of greater dianietcrthan the body of the shell,

which is adapted to engage a corresponding thread in a groove 26 in a cap 27. This cap. is provided with the usual central hole '28 through which the electric conductors (not shown) pass and with a recess 29 within which the conductors may be tied if preferred- Insulating block 19 is provided in itsoutcr side with grooves, 30 which. receive the locking springs and in its rear end with a recess 31 which receives one of the binding screws, the wall of the recess insuring its perfect insulation from the other binding screw.

32 and 33 denote the binding screws. Binding screw 32 engages a plate 34 which is connected by means of a screw 35 to an extension 36 of contact plate 21, said screw securing both plate 3-1tandthe contact plate to the insulating block. Binding screw 33 engages a plate 37 which is secured to the" insulating block bya screw 38 and to which a contact plate 39 is secured which bears upon the inner shell. The course of the current is as follows: from binding screw 32" shell through locking springs 22 to the inner shell and through contact 37 to binding screw 33.

An important feature of. the present i11- vention 'is that both members of the plug. may be removed together from a receptacle without separating the members. In order to accomplishthis result. I provide bosses or projections 40, two in the present instance, which projcct into groove 14 and lie in the path of projections on the locking springs. To remove the plug from a receptacle the inner member is rotated by means of the knurled. ring and the outer member is at once picked up and carried with it through the engagement of a projection on a locking spring with one of the bosses on the screwshcll and the plug complete is plate 39 and plate u to,

turned out. The two members are connected or disconnected when required by a straight push or pull, the pro'ectlons on the locking springs passing rea ily over the threads and engaging the groove with suflicient pressure to retain the members'securely together under the ordinary conditions of use but permitting them to be separated by a moderate pull. In connecting the members,

should a projection on a spring come in alinement with one'of the bosses, one of the members is turned sli htly and complete en agement will take place.

aving thus described my invention claim;

1.;- A screw shell having at its forward end an insulating head carrying a contact plate and a contact spring connected theregroove and bosses in said groove.

and having on its inner side a circular 1 2. An attachment plug comprising a A screw shell having at its forward end an insulating head carrying a contact plate and a: contact spring connected therewith and having on itsinner side a circular groove, an inner shell carrying locking springs with projections engaging said groove, an insuwithin said shell carrying a.-

lating block contact plate adapted to engage the contact spriniland electrical connections.

3. attachment plug comprising a screw shell having at its forward end an insulating head carrying a contact plate and a contact spring connected therewith andand bosses in said groove. an insulating head I at the forward end of said shell having a contact plate and a contact spring secured thereto, an inner shell carrying locking springs adapted to engage said groove and bosses, for the purposes set forth,'an insulating block within said shell carrying a contact plate adapted to engage the contact sprin and electrical connect1ons.

5. r n attachment plug comprising a screw shell having a circular groove an bosses therein and at its forward end an insulating head carrying a contact plate, an inner shell carrying locking springs adapted to en age said groove and bosses, an insulating block in the inner shell binding screws carried by said block and electrical connections from one binding screw to the screw shell and from .the other binding screw to the contact plate.

6. An attachment plug comprising a screw shell havin a circular groove and bosses therein and an inner shell carrying locking springs having projections adapted to engage said groove to detachably secure said shells together and to engage said bosses so that the shells may be detached frplm a-socket without separation from each ot er.

l 7 In an attachment plug, the cornhination with a screw'shell having a circular groove and bosses therein and an insulat ing head carrying a-contact plate and contact spring, of an inner shell carrying look ing springs having projections adapted to engage sald groove and bosses, for the pur poses set forth, an insulating block in the inner shell carrying a contact plate adapted to engage the contact spring-and electrical connections. i

In testimony whereof I aiiix my signature in presence of two witnesses;

HARVEY Hons-ELL.

-Witnesses: A. M. WOOSTER,

S. W. A'rHnR'roN. 

